For over a decade, the math for residential solar in California was simple: put panels on your roof, sell excess power to the grid at retail rates, and use those credits to pay for your nighttime energy use. Under that framework — known as Net Energy Metering 2.0 — standalone solar panels could pay for themselves in 6 to 8 years, and homeowners could effectively zero out their electric bills.
That era officially ended with NEM 3.0 (technically called the Net Billing Tariff), which took effect in April 2023. Under the new rules, the value of the excess solar energy you export to the grid has dropped by roughly 75%. What used to be worth $0.30 per kWh or more is now worth as little as $0.05 to $0.08 during many hours of the day.
What this means for homeowners
If you install standalone solar today — panels only, no battery — you are effectively giving your daytime excess power to the utility for pennies, while still paying top dollar to buy electricity back during the expensive evening hours (4:00 PM to 9:00 PM). The payback period for panels-only systems has stretched from 6–8 years to 12–15 years or more in many cases. The ROI no longer pencils out.
The battery changes everything
With a battery, instead of exporting your excess daytime solar to the grid for pennies, you store it. When utility rates spike during the 4:00 PM to 9:00 PM peak window, your home automatically stops pulling from the grid and runs entirely on your stored solar power. You avoid the most expensive electricity of the day — every single day — and the payback math snaps back into the 7-to-10-year range.
Why some installers aren’t telling you this
Volume residential solar installers have business models built around selling panels as quickly and cheaply as possible. Many of them are still quoting standalone solar systems using financial projections that assume NEM 2.0 economics — because the numbers look better and the sale is easier to close. If a solar company gives you a quote today for panels without a battery, ask them to show you the export rate assumptions in their savings calculation. If those numbers don’t reflect NEM 3.0 reality, the promised savings won’t materialize.
How we design for NEM 3.0
Every residential system we design at Symmetric Energy includes battery storage as a core component, not an add-on. We model each system against the homeowner’s actual usage patterns, the current NEM 3.0 export rates (which vary by time of day and season), and the time-of-use rate schedule they’re on.
The goal is to maximize self-consumption — using as much of your own solar power as possible, storing the rest for peak hours, and minimizing grid exports to the lowest-value periods. This approach consistently delivers strong returns even under the new rate structure.
If a solar company gives you a quote today for panels without a battery, they are selling you yesterday’s technology for tomorrow’s rate environment. The economics have fundamentally changed, and your system design should reflect that.